Spin torque MRAM fabrication using negative tone lithography and ion beam etching

US9705077B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Anthony J. Annunziata · Stamford, US
• Armand A. Galan · New York, US
• Steve Holmes · Cambridge, GB
• Eric A. Joseph · White Plains, US
• Gen P. Lauer · Mahopac, US
• Qinghuang Lin · Yorktown Heights, US
• Nathan P. Marchack · White Plains, US

Key dates

• Filing date: Aug 31, 2015
• Grant date: Jul 11, 2017
• Expiry date: Aug 31, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B61/00
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method for forming a memory device includes masking a photoresist material using a reticle and a developer having a polarity opposite that of the photoresist to provide an island of photoresist material. A planarizing layer is etched to establish a pillar of planarizing material defined by the island of photoresist material. A metal layer is etched to form a metal pillar having a diameter about the same as the pillar of planarizing material. A memory stack is etched to form a memory stack pillar having a diameter about the same as the metal pillar. A magnetoresistive memory cell includes a magnetic tunnel junction pillar having a circular cross section. The pillar has a pinned magnetic layer, a tunnel barrier layer, and a free magnetic layer. A first conductive contact is disposed above the magnetic tunnel junction pillar. A second conductive contact is disposed below the magnetic tunnel junction pillar.